1. Field of the Invention
The present invention relates to projection-type display apparatuses, namely, projectors, for projecting images on screens by illuminating liquid-crystal panels or the like with light emitted from light sources.
2. Background of the Related Art
Projection-type display apparatuses for projecting images on screens are used to project dramatic images at event sites. The screens are disposed at positions higher than the projection-type display apparatuses so as to be easily seen by many people. Therefore, the projection-type display apparatuses project toward the screens in upwardly inclined directions from the projection-type display apparatuses. When an image is projected on a screen in such a way in an upwardly inclined direction, however, the frame (display frame) of a projected image, which is a rectangle, for example, is projected in a distorted state, i.e., as if it were a trapezoid.
To solve such a problem, a projection-type display apparatus which applies image-distortion compensation (hereinafter called keystone-distortion compensation) to an image to be projected to prevent the frame (display frame) of a projected image from being projected in a distorted state as if it were a trapezoid on a screen is disclosed, for example, in Japanese Unexamined Patent Application Publication No. Hei-10-111533.
In the above-described conventional projection-type display apparatus, the keystone-distortion compensation is applied only to images input from an image source, such as a personal computer, to the projection-type display apparatus, and the keystone-distortion compensation is not applied to a (OSD; on-screen display) menu image to be displayed on the screen.
Therefore, if the OSD menu image is superposed on an image input from a personal computer and projected on the screen, only the OSD menu image has a keystone distortion.
The present invention has been made in consideration of the foregoing condition. An object of the present invention is to provide a projection-type display apparatus which reduces the keystone distortion of an OSD menu image or which makes the distortion inconspicuous.
A projection-type display apparatus of the present invention includes an on-screen-display-menu generating section that generates image data corresponding to an on-screen-display menu; an image synthesizing section that synthesizes image data for projection sent from an image source and the image data corresponding to the on-screen-display menu; and an image-distortion compensation section that applies image-distortion compensation processing used to reduce the distortion of the projected image obtained when an image is projected in an inclined direction against a screen, to the image data synthesized by the image synthesizing section.
According to the present invention, keystone-distortion compensation is applied to the synthesized image obtained by synthesizing the image data corresponding to the on-screen-display menu and the image data for projection, sent from the image source. Therefore, not only the keystone distortion of the image for projection but also that of the on-screen-display menu projected on the screen is reduced.
It is preferred that the projection-type display apparatus further include an image control section that applies image processing to the image data for projection output from the image source so as to conform to a projector that projects an image on a screen, and for sending to the image synthesizing section.
According to the present invention, the image processing is applied to the image data for projection output from the image source so as to conform to the projector that projects an image on a screen. Therefore, the keystone distortion of the image data of the on-screen-display menu, to which it is not necessary to apply the image processing, is reduced without converting the data structure.
It is further preferred that the projection-type display apparatus further include an image control section that selects either the image data for projection sent from the image source to the image synthesizing section or image data output from the image-distortion compensation section, and for applying image processing so as to conform to the projector that projects an image on the screen.
According to the present invention, whether the image processing is applied to the image data of the on-screen-display menu so as to conform to the projector before synthesis or after synthesis can be switched.
A projection-type display apparatus of the present invention includes an on-screen-display-menu generating section that generates image data corresponding to an on-screen-display menu; a first image-distortion compensation section that applies image-distortion compensation processing used to reduce the distortion of the projected image obtained when an image is projected in an inclined direction against a screen, to image data for projection sent from an image source; a second image-distortion compensation section that applies the image-distortion compensation processing correspondingly to the on-screen-display menu; and an image synthesizing section that synthesizes the image data for projection to which the first image-distortion compensation section has applied the image distortion compensation and the image data corresponding to the on-screen-display menu, to which the second image-distortion compensation section has applied the image-distortion compensation processing.
According to the present invention, keystone-distortion compensation is applied to each of the image data for projection, sent from the image source and the image data corresponding to the on-screen-display menu. Therefore, not only the keystone distortion of the image for projection but also that of the on-screen-display menu is reduced.
A projection-type display apparatus of the present invention includes an on-screen-display-menu generating section that generates image data corresponding to an on-screen-display menu; and a projection section that synthesizes the image data generated by the on-screen-display-menu generating section and image data for projection sent from an image source, and for projecting on a screen, and the on-screen-display-menu generating section generates the image data of a transparent on-screen-display menu.
According to the present invention, since only the letter-display image serving as the letter information of the on-screen-display menu is displayed on the screen, the keystone distortion of the on-screen-display menu can be made inconspicuous.
A projection-type display apparatus of the present invention includes an on-screen-display-menu generating section that generates image data corresponding to an on-screen-display menu; and a projection section that synethesizes image data generated by the on-screen-display-menu generating section and image data for projection sent from an image source, and for projecting on a screen, and the on-screen-display-menu generating section generates the image data of an on-screen-display menu so as not to have sharp corners and instead to have round corners.
According to the present invention, since the on-screen-display menu having round corners is used, the distortion of the frame of the on-screen-display menu is made inconspicuous.
A projection-type display apparatus of the present invention includes an on-screen-display-menu generating section that generates image data corresponding to an on-screen-display menu; a projection section that synethesizes the image data generated by the on-screen-display-menu generating section and image data for projection sent from an image source, and for projecting on a screen; and an image synthesizing section that synethesizes the image data corresponding to the on-screen-display menu and the image data for projection such that the image of the on-screen-display menu obtained after synthesis gradually changes to the image corresponding to the image data for projection as it approaches the periphery.
According to the present invention, since gradation is applied to the image of the on-screen-display menu, the distortion of the frame of the on-screen-display menu is made inconspicuous.
A projection-type display apparatus of the present invention includes an on-screen-display-menu generator that generates image data corresponding to an on-screen-display menu; an image synthesizer that synthesizes images data for projection sent from an image source and the image data corresponding to the on-screen-display menu; and an image-distortion compensator that applies image-distortion compensation processing used to reduce the distortion of the projected image obtained when an image is projected in an inclined direction against a screen, to the image data synthesized by the image synthesizer, and achieves the foregoing object by this configuration.